PURPOSE: To obtain a forming method of the installing structure of a connector which can form an installing base having a different installing angle, by a single metal mould for forming an installing base, even though the installing angle of a small part such as a connector is different.

CONSTITUTION: To a metal mould main body D for forming an installing base having an installing hole 1 of a small part 6 such as a connector, a male insertion member 4 to form the inner peripheral surface of the installing hole 1, and a projection or a recess groove 2 for holding a small part, formed on the inner peripheral surface, is made to install to a piece forming member installing hole d1 formed to the metal mould main body D by selecting the installing angle. And by a single metal mould main body D for forming installing base, and the piece forming member 4, an installing base B having an installing hole 1 of different installing angle of a small part 6 is formed.